Log debarking drum



April 11, 1961 MccLAY 2,979,090

LOG DEBARKING DRUM Filed NOV. 17, 1958 null- INVENTOR GORDON F McGLAY HIS T ORNEY ited States Patent LOG DEBARKING DRUM Gordon F. McClay, Lennoxville, Quebec, Canada, as-

signor to Canadian Ingersoll-Rand Co., Ltd., Montreal, Quebec, Canada, a corporation of Canada Filed Nov. 17, 1958, Ser. No. 774,518

2 Claims. Cl. 144-208) This invention relates to log barking devices, and more particularly to the drums of log barking devices. Heretofore, drums for devices of the type to which this invention appertains were generally fabricated by riveting. However, this mode of :assembly has several known disadvantages, such as the time delay incurred in drilling the rivet holes and the weakening of the members in which such holes are formed. It is accordingly, one object of this invention to provide a log barking drum of welded construction.

Another object of this invention is to assemble the various members of the drum in such a manner that the transfer of stresses therebetween is a gradual rather than abrupt process.

Further objects of this invention will become obvious in the following specification and accompanying drawing in which,

Figure 1 is a side view of an end portion of a log barking drum constructed in accordance with the practice of the invention,

Fig. 2 is an enlarged detail of Figure 1 showing the marginal portion of a hoop and the manner in which the fingers of such marginal portion are welded to the drum staves, and

Fig. 3 is an enlarged cross-sectional view of Figure 1 taken along the line 3-3 looking in the direction of the arrows.

Referring to the drawings it is to be understood that only one-half of the drum is shown in Fig. l as the opposite end portions of the drum are substantially alike. The drum is generally cylindrically shaped and is rotatably supported on flanged rollers 11 in which ride annular tracks or tires 12 encircling the drum and mounted thereon. Rotation of the drum 10 is facilitated by means of a girth gear 13 encircling and secured to the drum 1% and engaging a drive pinion 14 mounted on a drive shaft 15 supported by members 16 (one only of which is shown) and rotated by any conventional type motor (not shown).

The drum construction includes several relatively spaced axially aligned hoops and a plurality of elongated staves 18 mounted in spaced parallel relation around the periphery of the hoops and secured thereto by welding.

In operation, logs are dumped into one end of the drum 10 and tumbled about within the drum as they move toward the opposite end to be discharged. The bark is stripped from the logs due to the relative longitudinal and rotational movement therebetween. To assure further that the logs will be stripped clean in passing through the drum it the longitudinally disposed ribs, or staves, 18 are mounted on the inner periphery of the drum 10 thereby presenting an irregular surface to the log for increasing or accentuating relative movement between the logs. To this end, the staves 18 have a generally U-shaped cross sectional form and the marginal or free end portions 19 are turned outwardly to provide surperiphery of the collar, or hoops, 20 to which they are secured.

The hoops 20 are positioned at predetermined spaced intervals with respect to each other along the length of the staves Iii-the space between the hoops 26 being determined by the strength of the staves 1 8. It is on these hoops that the girth gear 13 and the tires 12 are mounted.

The ends of the staves 18 are secured to end covers 21 having central openings through which the logs are loaded in the drum 10 and dumped therefrom. The diameter of the end openings of the drum is generally somewhat less than the inner diameter of the drum 1:) thereby providing a rim or internal flange at the opposite ends of the drum 10 to retard the movement of the logs through the drum 10.

'In the form of the invention as shown, the staves 18 are welded to the hoops 20 and the end covers 21 and in order to prevent the abrupt transfer of load or stress therefrom to the staves 18, the marginal portions, indicated in general by 120, of the hoops 20 and the inner marginal portions, indicated in general by 122, of the end covers 21 are scalloped to provide a series of spaced axially extending tapered projections 22. Each projection is slotted at its mid-portion so as to provide at the outer end portion of each projection 22, a pair or" outwardly tapered fingers 24 and 26. It is to be noted that the distance between the approximate center line of each projection 22 is equal to the width of a stave 18 plus.

the distance between adjacent staves 18, and further that the staves are positioned relative to the hoop such that the slot 28 is approximately midway between the opposed edges 30 of adjacent staves.

As a consequence of this construction and arrangement, with reference to any one stave as viewed in Fig. 2, the adjacent fingers 24, 26 of adjacent projections are secured to the opposite edges of a stave. Specifically, the right hand finger 26 of one projection 22 extends along and overlies the left edge of the associated stave 18, and the left finger 24 of the adjacent projection 22 extends along and overlies the right hand edge of the same stave. Explained in another way and with reference to the rotation of the drum, and again referring to one stave only, the lagging finger 26 of the leading projection 22 overlies the leading edge of the stave 18, and the leading finger 24 of the lagging projection 122 overlies the lagging edge of the stave 18.

The staves 18 are secured to the hoops by means of welding at 32 along the edges 30 of the staves and the inner periphery of the hoops. With this construction, it is possible to obtain uniform strength of welding along the entire line of weld, and moreover due to the flexibility of the projections 22 and the fingers 24 and 26 the impact forces and other high loading of the staves is trans mitted gradually to the hoops. That is, any loading of the staves which tend to bend the staves, results also in the bending of the projections 22 and the fingers 24 and 26 and the loading or stress in the projections, fingers and hoop increases gradually from the outer end of the finger towards the center of the hoop to a point inward of the bottom of the scalloped portion 21 of the marginal portions of the hoops.

It will be noted that with this construction that there is provided, in eflect, a double flexible barrier between the marginal portion of the hoop and the main body of the hoop to obtain gradual transmission of the load stress to the hoops. More particularly, the fingers 24 and 26 are relatively more flexible than the projections 22, and the projections 22 are relatively more flexible than the main body of the hoop. As a consequence of this structure, the drum is capable of operating under extreme load conditions over extended periods without rupture or failure of the weld connection between the hoops and the staves.

i In the particular form of the invention shown; it will be noted that the welds for each stave extends along the inner periphery of the hoops starting at a point located slightly inward, relative to the center of the hoop, of each finger.

that the strength of the tips of the fingers might be effected by the application of heat during the welding ing outwardly tapered projections, each of said projec-- tions being divided to form outwardly tapered fingers, the

This was found to be a desirable construc- 47 tion in cases where the material of the hoops were such one side of each finger for its entire length overhanging an edge of an associated stave, said hoops being secured to the staves by a lineal weld between the hoop and stave and extending from the end of the finger along the inner periphery of the hoop.

2. A log debarking drum claimed in claim 1 wherein said staves are U-shaped in cross-sectional form and comprise marginal portions turned outwardly to provide surfaces in face relation to the inner surfaces on said fingers, and the weld being to such inner surfaces and the edges of said stave marginal portions.

References Cited in the file of this patent UNITED STATES PATENTS 2,684,092 Dick July 20, 1954 FOREIGN PATENTS 163,484 Sweden June 10, 1958 

